Closure



R. B. WAITE Jan. 22, 1946.

CLOSURE Filed Jan. 9, 1942 INVENTOR /84P// 5 4/9/75 B a. HIS ATTORNEYS Patented Jan. 22, 1946 CLOSURE Ralph B. Waite, Springville, N. Y., assignor, by

mesne assignments, to Sterling Drug Inc., Wilmington, DeL, a corporation of Delaware Application January 9, 1942, Serial No. 426,116

Claims.

My invention relates to a new closure for bottles, vials and the like adapted to contain medicinal and other liquid preparations.

My new closure is of the type used when medicinal preparations are withdrawn from stoppered bottles by means of a hypodermic syringe, the needle of which is introduced into the bottle through the stopper material. It is characterized particularly by the ease with which the medicinal preparation can be withdrawn and by the ease with which the needle of the hypodermic syringe can be inserted as well as by the extreme simplicity of its construction.

The first closures of this type developed by the art were constructed with the sol purpose of making them capable of being pierced by the needie of a hypodermic syringe. Stoppers of somewhat later construction featured the idea of maintaining the pierceable material in the stopper under compression so as to avoid contamination of the medicinal solution by contact with air seeping through the perforations made by the needle. This was accomplished by making the pierceable material resilient and making the outer dimensions of the stopper slightly larger than the neck of the bottle with which it was intended to be used. Although this device had the desired result, it created other problems. The compressive stress on the resilient material makes the stopper relatively difficult to pierce with a needle. Furthermore, when a medicinal solution is withdrawn from a bottle provided with such a closure, the pressure within the bottle progressively decreases until it finally becomes so much lower than atmospheri that further withdrawal is difiicult or impossible. A considerable waste of medicament inevitably results. More recently the problem has been attacked by providing pierceable stoppers with air valves and chambers filled with sterilizing cotton. These, howevenare difficult to manufacture and therefore expensive, and are prone to leak.

One object of my invention, therefore, is to provide a closure not having the aforementioned disadvantages.

Another object of my invention i to provide a closure of simple construction which permits easy withdrawal of the medicinal solution from the container.

Still another object is to provide a closure of simple construction provided with means for sterilizing any air entering the container upon withdrawal of the medicinal solution.

A concomitant object is to provide a closure that will permit easy withdrawal, but does not allow leakage of the medicinal solution from the container.

Another concomitant object of my invention is to provide a closure that can be pierced easily with the needle of a hypodermic syringe.

These and other objects and advantages will be understood by those skilled in the art or will be apparent or pointed out hereinafter.

I have found that these objects can be accomplished by equipping a closure provided with a channel, with a thin diaphragm of resilient, organic material that is normally under neither tension nor compression.

In the accompanying drawing which illustrates preferred embodiments of my invention:

Fig. 1 is a cross-sectional elevation of one form of closure responding to the present invention,

Fig. 2 is a cross-sectional elevation of the closure of Fig. 1 showing it in place on a medicinal container and also the manner in which a charge of the liquid preparation is withdrawn from the container by means of a hypodermic syringe; and

Fig. 3 is a section through a container equipped with a modified form of my new closure and a cap therefor.

Like numerals designate corresponding parts throughout the various views of the drawing.

It is to be understood, of course, that the illustrated embodiments of my invention are intended as examples and not as restrictive or limitative and that the different embodiments may be used interchangeably.

Closure I0 may be made of any resilient or non-resilient material and is preferably made of an elastic, thermoplastic material such as natural or synthetic rubber. The cylindrical side wall portion H may have a shoulder l2 to engage a complementary shoulder in the neck of the container l3. If desired, the closure may be equipped with a skirt l4 that can be folded down over the exterior surface adjacent the mouth of container 13.

The closure i0 is provided with a channel I5 leading to a chamber is preferably filled with a loosely packed air-filtering material, such as cotton, which may be sterilized. Chamber I8 is formed partly by the end wall of closure Ill and partly by a sealing diaphragm IT. This diaphragm I1 is made of a tough, resilient thermoplastic material such as natural rubber, synthetic rubber or a rubber substitute. I prefer to use pure Para rubber. As synthetic rubber I may use, for example, synthetic rubbers such as those derived from butadiene, chloroprene and the like. Rubber substitutes include elastic polymerization prodnets of aliphatic unsaturated compounds such as polymerized acryclic acid esters, dienes and interpolymers thereof, elastic vinyl compounds and polyisobutylenes and interpolymers thereof. In the specification and claims I hereinafter refer to these materials, including natural rubber, as rubberlike materials.

Diaphragm I1 is preferably an integral part or elongation of the material forming channel 15 and chamber t6, shown as unitary in Figs. 1 and 2, but it may be a separate piece of rubber-like material with its edges securely attached to the main body of the closure ID as shown, for example, in Fig. 3. When the diaphragm I1 is a separate piece, its union with the main body of the closure I must, of course, be capable of resisting repeatedly the tendency of the diaphragm to tear away when it is subjected to stress as, for example, when the diaphragm is pierced by the needle of a hypodermic syrin e. In either case, it is particularly important that diaphragm ll be fixedly secured without strain, i. e., the main body of closure I0 should exert n0 compressive or tensile force on the diaphragm. In other words, the diaphragm material, although fixedly secured to the closure proper, should hang loosely as a thread, for instance, would hang if its two ends were secured at points spaced from one another by a distance less than the free length of the thread. It is preferable to give diaphragm i! a bulb-like shape as shown in the drawing. The thickness of diaphragm I'I should be as small as possible without, of course, causing it to rip or tear, or allowing filtering material to be Pushed into the container when the diaphragm is pierced by a hypodermic needle. The lower limit of thickness, therefore, varies with, and depends upon. the quality of the material. I have found that when diaphragm I1 is made of pure Para rubber, its optimum thickness is about 0.04 inch. In no event, however, should the thickness of the diaphragm material be so great that when it is pierced by the needle of a hypodermic syringe and a difierential pressure is created, it will prevent air from flowing past the needle.

When it is desired to withdraw liquid medicinal preparation l8 from container l3 by means of hypodermic syringe l9, the needle 20 of syringe I9 is passed through channel l5 and chamber is and made to pierce sealing diaphragm I1. N eedle 20 pierces diaphragm I! very easily because the latter is so thin. As long as the pressure within container I3 remains substantially equal to the atmospheric pressure, the diaphragm l1 forms an effective seal around needle 20 so as to prevent leakage of the medicament into chamber 16 or of air into the container. When the medicament is withdrawn through needle 20, however, the diaphragm I1, apparently for the reason that it is not subjected to compressive stress, allows air from chamber iii to leak past needle 20 into container i3 until the pressure in the container is made substantially equal to that of the atmosphere. The filtering material within chamber 16 filters the air before it passes into the container. When the needle is withdrawn, the diaphragm will close up and efiectively seal the aperture.

The medicinal preparation may, of course, be introduced in any convenient manner. Thus, for example, container 13 may simply be filled with the medicament under sterile conditions and sealed by placing closure [0 in position. Another method is to introduce the medicament into the container by means of hypodermic syringe I9. the needle of which is passed through channel I5 and chamber l6 and made to pierce sealin diaphragm 11. Preferably the filling is accomplished with the aid of a double needle which is made to pierce the fiat part of the closure without piercing diaphragm l1. One barrel of the needle introduces the medicament while the other relieves the pressure built up as the containerv is filled. When the needle is withdrawn, the

rubber-like material of the closure effectively seals the opening.

When container I3 is not in use, it is desirable, although not necessary, to cover closure ID with a protective cap 2|. This may be of any suitable material, such as metal, plastic, glass, hard rubber or the like. Cap 2| is equipped with a screw thread or cam member 22 adapted to engage complementary projections 23 on container l3. The interior of cap 2| is preferably provided with a disinfectant, such as sterilized cotton or the like, which will be pressed down upon the face of closure I0 when cap 2| is tightened so as to protect chamber l6 and channel [5 against contamination.

It is surprisin that although air may leak past needle 20, diaphragm I1 will effectively seal the container when the needle is withdrawn and the pressure differential has been equalized. This is due, no doubt, to the elasticity of the diaphragm material and especially to the fact that under normal conditions it is neither under compressive nor tensile stress. Diaphragm I! also has the function of relievin excess internal pressure when the container is filled.

It is to be clearly understood that various additions, omissions, substitutions and modifications may be made without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. A container closure which comprises a hollow cylindrical body portion open at one end and provided with a transverse end wall portion at the other end, said end wall portion being provided with a channel therethrough and with an enlarged open-ended recess with which said channel communicates, and a thin, resilient, imperforate diaphragm extending across the open end of said recess to define an enlarged chamber, said diaphragm being composed of elastic material which is capable of being easily pierced by a hypodermic needle and which is self-sealing after the removal of the hypodermic needle therefrom, said diaphragm being of such thickness that it is adapted to permit entrance of air between the material of the diaphragm and the needle in response to atmospheric pressure while the contents of the container are being withdrawn through the needle.

2. A container closure in accordance with claim 1 in which the imperforate diaphragm is composed of rubber about 0.04 inch in thickness whereby it is self -sealing when a hypodermic needle pierces and is then withdrawn from the same and is adapted to permit entrance of air between the rubber and the needle as the contents of the container are being withdrawn through the needie.

3. A container closure in accordance with claim 1 in which an air filtering and sterilizing material is disposed in the said enlarged chamber and is maintained in position by the said imperforate diaphragm.

4. A container closure in accordance with claim 1 in which the said diaphragm normally seals from the atmosphere the contents of the container to which the said closure is applied.

5. A container closure in accordance with claim i in which the thin, resilient, imperforate diaphragm is concavo-convex in cross section and is in a substantially unstressed condition.

RALPH B. WAITE. 

